Carton blanks for contact lens containers are shipped from the carton supplier with most of the necessary information printed on them, with blank areas on the cartons for receipt of variable information, such as, the lot number, barcodes, design (e.g., power), and expiration date of the product. Carton blanks are often supplied having pre-glued areas, e.g. the lid or side flaps. The pre-glued areas of the carton have two layers of paper, and therefore, these areas of the carton are not flat. Further, fold lines in the carton, which form the edges at the intersection of two surfaces cause the surfaces of the carton to be irregular. Attempts to print on the flat blanks can result in illegible printed information.
One solution is not to print on the carton and to add additional information by adding an adhesive label to the carton; however, adhesive labels are expensive. Another alternative is to emboss areas of the carton which do not overlap when the carton is flat; however, that limits the areas which can be printed on, and cannot readily be used to print some kinds of information, e.g. barcodes.
There is a need for an apparatus to remedy the problem of printing on a partially pre-glued carton so that legible print can be added to the carton.